Integrated Furnace for Combustion/Gasification of Biomass Fuel for Tobacco Curing

A new system for providing heat for the flue-curing of tobacco was developed by modifying the conventional direct combustion of biomass fuel (bio-fuel) such that the energy stored in the fuels was fully utilized. The system consisted of an integrated furnace with a heat dissipation structure for combusting and gasifying bio-fuel including solid fuel as well as combusting the generated gas, and a heat exchanger with a special flue pipe layout. The new device was tested through experiments in different tobacco-growing areas, using the controlled direct combustion of coal and biomass fuel for flue-curing in a bulk curing barn. The results showed that the distribution of temperature in the longitudinal section of the new system exhibited a regular temperature transition pattern corresponding to the solid fuel and gas combustion areas. The amount of carbon monoxide in the flue gas at the chimney exit indicated that the burning of the biomass briquette fuel was more complete, with less than 1.7% carbon monoxide generated. The thermal efficiencies of the biomass briquette fuel and firewood were 55.26 and 53.17%, respectively, which were higher than that of coal (49.52%). The newly developed integrated furnace would be well suited for tobacco curing in tobacco-growing areas, and could be used commercially for drying agricultural products on different scales.